Descriptions:1. Tap and die set are suitable for making or repairing male and female threads, good for general purpose applications. Tap and die are both right hand thread.2. Can be used to process through holes in maintenance and repair work. Great for drilling and tapping alloy steel , die steel, cast iron, ferrous and non-ferrous materials etc..3. High speed steel machine screw tap provides combination of hardness and toughness for wear resistance. Alloy tool steel round die features good abrasion resistance. Tap and die set are sharp and durable, and with clear threads to meet the processing requirements.4. Round dies can be used with die wrench (not included). The fastening screw in the middle of the wrench should be inserted into the slot of the die and tightened.